Normalized Power (NP): Understanding, Interpreting, and Benchmarking Your Scores

What is a Good Normalized Power Score?

A "good" Normalized Power (NP) score is highly contextual, depending on an individual's fitness level, the type and duration of the athletic event, and specific training goals; it represents the physiological cost of a variable effort more accurately than average power.

Understanding Normalized Power (NP)

Normalized Power (NP) is a proprietary algorithm developed by TrainingPeaks that provides a more accurate measure of the physiological cost of a workout or race with variable intensity, particularly in cycling. Unlike simple average power, which can be skewed by periods of coasting or very high intensity, NP accounts for the fact that the human body responds non-linearly to changes in power output. Short bursts of high power are disproportionately more taxing than sustained moderate power, and NP reflects this physiological reality.

Why is it used? Imagine two cyclists completing a 60-minute ride.

• Cyclist A rides at a constant 200 watts for the entire hour. Their average power is 200W, and their Normalized Power is also 200W.
• Cyclist B rides for 60 minutes with numerous sprints, descents, and accelerations, resulting in an average power of 200W. Due to the variable effort and the body's higher physiological stress response to these fluctuations, Cyclist B's Normalized Power might be 230W or higher.

NP provides a better metric for quantifying the metabolic stress and, consequently, the training stimulus of a variable effort.

Factors Influencing a "Good" Normalized Power Score

Determining what constitutes a "good" NP score is not about a single number, but rather a complex interplay of several factors:

• Individual Fitness Level: An elite cyclist will naturally have a much higher absolute NP than a recreational rider. It's more meaningful to compare NP to an individual's own Functional Threshold Power (FTP).
• Event Type and Duration:
  • Time Trials: Tend to have NP very close to average power, as the effort is sustained and consistent.
  • Criteriums/Road Races: Characterized by frequent accelerations and decelerations, leading to NP significantly higher than average power.
  • Long Endurance Rides: NP might be slightly higher than average power due to minor variations.
• Terrain: Hilly courses or routes with frequent stops and starts will inevitably lead to a higher NP relative to average power compared to flat, open roads.
• Training Goals: A "good" NP might be one that aligns with the specific demands of a target event or the physiological adaptations a coach is trying to elicit.

Interpreting Your Normalized Power Scores

To effectively use NP, consider these interpretive strategies:

• Relative vs. Absolute Values: While absolute watts (e.g., 250W NP) are useful, comparing NP to your body weight (W/kg NP) provides a more standardized measure, especially for climbing or comparing yourself to others.
• Training Zones: NP can be used to assess if a workout, despite a low average power, effectively hit a desired training zone due to its variable nature. For example, a "Zone 2" endurance ride might have an average power in Zone 2, but an NP that creeps into Zone 3, indicating a higher physiological cost.
• Variability Index (VI): This is calculated as Normalized Power divided by Average Power (NP/AP).
  • A VI close to 1.0 (e.g., 1.0-1.05) indicates a very steady effort, like a time trial.
  • A VI between 1.05-1.15 is typical for rolling terrain or group rides.
  • A VI above 1.15 suggests a highly variable effort, such as a criterium, mountain biking, or a very "punchy" road race. A higher VI generally means more physiological stress for a given average power.
• Trends Over Time: A "good" NP score might be one that shows an increase over similar efforts, indicating improved fitness, or one that aligns with performance goals. Conversely, a drop in NP for a given effort might signal fatigue or overtraining.

Benchmarking Normalized Power: What to Aim For

Instead of a universal "good" NP score, it's more productive to consider NP in relation to your Functional Threshold Power (FTP), which is the maximum power you can sustain for approximately one hour.

• For a sustained effort (e.g., a 1-hour time trial): A "good" NP would be very close to your FTP, ideally within 95-100% of your FTP.
• For a moderately variable effort (e.g., a long group ride on rolling terrain): A "good" NP might be around 80-90% of your FTP for several hours, reflecting a sustainable but challenging pace.
• For highly variable efforts (e.g., a 1-hour criterium race): A "good" NP could exceed your FTP, perhaps 105-115% or even higher, due to the intense bursts that elevate physiological stress, even if average power is lower. This indicates a strong ability to handle repeated high-intensity efforts.

General Benchmarks (W/kg NP for a 60-minute race-like effort):

• Recreational Rider: 2.0-3.0 W/kg
• Trained Amateur/Enthusiast: 3.0-4.0 W/kg
• Strong Amateur/Cat 3-4 Racer: 4.0-5.0 W/kg
• Elite/Professional: 5.0+ W/kg

These are rough guidelines, and the actual "good" score for you is one that reflects your current capabilities, challenges you appropriately, and contributes to your training goals.

Practical Applications for Training

NP is a powerful tool for athletes and coaches:

• Pacing Strategies: During races, understanding your NP relative to your FTP can help you gauge if you're over-exerting yourself in variable conditions.
• Workout Analysis: NP provides a more accurate reflection of the physiological stress of a training session than average power, allowing for better tracking of training load (e.g., using Training Stress Score - TSS, which is derived from NP).
• Performance Tracking: Monitoring NP over time for similar efforts can reveal improvements in your ability to sustain higher power outputs under variable conditions.

Limitations and Considerations

While valuable, NP has limitations:

• Power Meter Accuracy: NP is only as reliable as the power meter providing the data. Regular calibration is crucial.
• Drafting and External Factors: Drafting in a group ride reduces the power output required, which will lower NP, even if the physiological cost of staying with the group is high. Wind and road surface also play a role.
• Individual Variability: While NP is based on a physiological model, individual responses to variable efforts can still differ.

Conclusion: The Nuance of "Good" Power

Ultimately, a "good" Normalized Power score is not a fixed number but a dynamic metric evaluated within the context of your individual physiology, training history, and specific athletic objectives. It's a sophisticated tool that moves beyond simple averages to provide a more truthful representation of the demands placed on your body during variable efforts. By understanding and consistently tracking your NP, especially in relation to your FTP and Variability Index, you gain invaluable insights for optimizing your training, pacing, and overall performance.